1670s, "principal character in a story, drama, etc.," from Greek prōtagōnistēs "actor who plays the chief or first part," from prōtos "first" (from PIE root *per- (1) "forward," hence "in front of, first, chief") + agōnistēs "actor, competitor," from agōn "contest" (from PIE root *ag- "to drive, draw out or forth, move").
The general meaning "leading person in any cause or contest" is from 1889. The mistaken sense of "advocate, supporter" (1935) is from misunderstanding of Greek prōt- as Latin pro- "for." Compare antagonist. Deuteragonist "second person or actor in a drama" is attested from 1840.
"one who opposes, an adversary, an antagonist," 1580s, from noun use of Latin opponentem (nominative opponens), present participle of opponere "oppose, object to," literally "set against, set opposite," from assimilated form of ob "in front of, in the way of" (see ob-) + ponere "to put, set, place" (see position (n.)). Originally "one who maintains a contrary argument in a disputation;" the general sense is by 1610s.
To be in opposition is not to be a nihilist. And there is no decent or charted way of making a living at it. It is something you are, and not something you do. [Christopher Hitchens, "Letters to a Young Contrarian," 2001]
Latin contrarius (adj.) also was used as a noun meaning "an opponent, an antagonist." In English history, contrariant (from French, from Medieval Latin contrariantem) was the name given to Thomas, Earl of Lancaster, and the barons who took part with him in the rebellion against Edward II, "because, on account of their great power, it was not expedient to call them rebels or traitors" [Century Dictionary].
Middle English drope, from Old English dropa "a small, spherical mass of liquid," from Proto-Germanic *drupon (source also of Old Saxon dropo, Old Norse dropi, Dutch drop, Old High German tropfo, German Tropfen (n.)); see drop (v.).
Sense of "minute quantity of anything, least possible amount" is from c. 1200. Meaning "an act of dropping" is from 1630s; of immaterial things (prices, temperatures, etc.) from mid-19c. Meaning "lozenge, hard candy" is 1723, from resemblance in shape. Meaning "secret place where things can be left illicitly and picked up later" is from 1931. Theatrical meaning "painted curtain dropped between scenes to conceal the stage from the audience" is by 1779.
Drop in the bucket (late 14c.) is from Isaiah xl.15 [KJV]. At the drop of a hat "suddenly" is from 1854. To get the drop on "be prepared before one's antagonist" originally was Old West gunslinger slang (1869).
late 12c., "loss, lack; " c. 1200, "regret occasioned by loss or absence," from Old English miss "absence, loss," from source of missan "to miss" (see miss (v.)). Meaning "an act or fact of missing; a being without" is from late 15c.; meaning "a failure to hit or attain" is 1550s.
Phrase a miss is as good as a mile (1761) was originally an inch, in a miss, is as good as an ell (1610s; see ell). To give (something) a miss "to abstain from, avoid" is attested by 1919, perhaps from earlier use of the term in billiards, "to avoid hitting the object ball" (1807).
There are few of the niceties of the game that require more care than that of "giving a miss," and particularly when the player wishes to mask the ball. I recollect a game I played with Mr. Burke, of Cheltenham. He went off, and doubled, as was his custom, the red ball nearly over the baulk corner pocket. Not feeling disposed, against so skilful an antagonist, to run the risk of playing for a canon off his ball, I gave a miss, thinking I had masked the ball. His eye, keen and penetrating, discovered at a glance that I had just left him room to pass. He played at the red ball and holed his own ball off it by a fine cut, and scored forty points from the break. [Edward Russell Mardon, "Billiards," London, 1849]